The present invention relates generally to methods and compositions useful for heat absorption, particularly in crash survivable protective enclosures for flight recorders used in aircraft and other vehicles operating over land and water. More particularly, the present invention relates to heat absorption compositions for use in a crash survivable enclosure which is capable of withstanding high impact, shock and mechanical penetration forces that commonly occur in a crash and the high temperatures, flames, and heat that often develop after a crash. The enclosure is designed to resist damage to solid state memory devices contained therein, even if the enclosure is subjected to immersion in fresh water or salt water for a prolonged period.
As a first aspect, the present invention provides a method for dissipating heat away from a heat sensitive device exposed to a high temperature environment. The method comprises surrounding the heat sensitive device with a composition comprising a polyoxymethylene polymer and optionally also a binder. The polyoxymethylene polymer undergoes endothermic decomposition when exposed to the high temperature environment. The composition absorbs heat from the high temperature environment during the endothermic decomposition of the polyoxymethylene polymer and dissipates heat away from the heat sensitive device.
As a second aspect, the present invention provides an enclosure for thermally protecting one or more heat sensitive devices from a high temperature environment. The enclosure comprises a) an outer housing having interior surfaces defining an interior cavity for containing one or more heat sensitive devices; and b) a heat absorption composition comprising a polyoxymethylene polymer. The composition occupies at least a portion of the interior cavity and substantially surrounds the heat sensitive devices. The polymer exhibits endothermic decomposition when the enclosure is subjected to the high temperature environment, and the composition absorbs heat from the high temperature environment during the endothermic decomposition of the polymer.
These and other aspects of the present invention are described further in the detailed description of the preferred embodiments of the invention which follow.